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T H E J O U R S A L OF I N D U S T R I A L A N D ENGILLTEERINGC H E M I S T R Y .
of this Journal, that very light naphtha is never employed for purposes of adulteration. I would say that I have come across several samples of contained a so-called turpentine-sold as “ pure ”-which high percentage of light naphtha, otherwise “gasoline.” R. H. ACOTT.
The combustion tube-see figure- resembles the familiar Hempel burette with the exception t h a t the cylinder i s open to the full diameter o f j t h e tube a t the base. This opening is closed by means of a stopper through which
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A PECULIAR CHLORATE EXPLOSION.’ A short time ago Dr. McKenna read a paper before this section on the hazard of explosives in which he gave account of several explosions caused by chlorate of potash. Since then several unusual cases of this kind have come to my notice. The facts as reported to me are as follows: A company in this city, makers of small castings, has been purchasing kegs from a second-hand dealer. These were used for packing castings for shipment. In the first case some of these kegs containing ingots of aluminum and zinc were being unloaded on a wharf when a keg took fire. The laborers supposed the kegs contained grains of powder and wanted to throw the entire lot into the river. The owners of the foundry could not account for the fire but thought some mysterious property of the zinc and aluminum might have caused it. No further investigation was made in this case. A few weeks ago ashipment of small iron castings was made to a neighboring city. When unloading one of the kegs from a truck, a slight explosion occurred; two men were slightly burned while the keg burned rapidly enough to heat the castings quite hot. On investigation i t was discovered that this keg had been obtained from a dye works and had contained chlorate of potash. The second-hand dealer claimed this lot of kegs had been thoroughly cleaned before delivery to the iron works b u t however that may have been either some chlorate had lodged in the crevices and escaped detection or else the wood had become saturated with i t from standing in a damp place. The jolting of the castings struck a spark which fired the mixture of chlorate and wood. Chlorate of potash is used by dyers and in this vicinity; where there are many dye houses, there must be a large number of these kegs to be disposed of in some manner. Fortunately all the fires of this kind of which I am aware occurred in the open air and did no damage. They might just a s easily have occurred in a warehouse or on shipboard. In fact the foundry using these kegs, ships castings abroad and it might be a very serious matter t o have a fire of this sort in the hold of a ship. Evidently purchasers of second-hand kegs have another danger to be guarded against, and we have another possible GEORGEC. DAVIS. cause for fires of mysterious origin.
A NEW COMB USTION PIPETTE. My experience of several years in gas analysis has led me t o construct a new form of combustion pipette that I have found superior to any other form I have yet used. My duties as Gas Analyst of Sioux City have afforded me ample opportunity to test this apparatus, and i t is with assurance that this form will be of interest to those engaged in gas analysis and of decided practical value that I bring the pipette t o public notice. I
Read before the Philadelphia Section, American Chemical Society.
Capillary tube.
Binding posts. Fig. 1 .
pass insulated wires connecting to a platinum spiral extending the entire length of the tube. One length of the heavy wire is insulated the full length of the cylinder to prevent a short circuit by the confining liquid, mercury. Glass insulation has been found to be the best. The lower ends of the wire pass through the weighted base to binding posts, which in turn may be easily connected to a battery. A leveling bulb connects to the tube by a heavy rubber tube. Among the advantages of this apparatus over the old
T H E J O U R K A L OF IA7DUSTRIAL forms may be mentioned the following: It can easily be cleaned. The pratinum spiral extending the full length of the tube insures complete combustion. This spiral can readily be removed for repairs in case of injury. The apparatus is convenient to handle and owing to its tall form connects with a Hempel pipette without the use of a stand. The apparatus can be obtained from Messrs. E . H. Sargent IT-ILFRED W.SCOTT. & C o . , Chicago.
DETERMINATION OF INSOLUBLE PHOSPHORIC ACID. * Ever since the organization of the Association of Official Agricultural Chemists the Official method for the determination of insoliible phosphoric acid has been confined to the one process; that is, digestion in neutral ammonium citrate for a definite length of time a t a stated temperature. From time to time some slight modifications have been proposed, b u t in the main, the method remains practically the same as i t was twenty-five years ago. One difficulty which has been experienced, is to make a n ammonium citrate which is exactly neutral, owing to the indefinite action of the solutioii on different indicators. The “official” method prescribes corallin as the indicator to be used in testing the neutrality of the solution. Any one who has tried this indicator knows how unsatisfactory i t is, and i t is safe to say that there is not one chemist in ten who depends upon i t for the final test. The optional method provides for first neutralizing with corallin as the indicator, and making the final test with cochineal after precipitating out the citric acid with calcium chloride. This procedure is also unsatisfactory, and as Dr. McCandless, referee of phosphoric acid for the A. 0. A . C. for the past year, truly said: “If a chemist has succeeded in getting his solution neutral or practically so, he will almost certainly get his out of joint b y attempting to make i t exact with calcium chloride solution.” The result is that different chemists employ different methods for standardizing the ammonium citrate solution, and hardly t u o solutions will be found of exactly the same neutrality. Instead of prescribing two methods which may give entirely different results the A. 0. A. C. should prescribe one method which can be easily worked and would prove satisfactory to a majority of the chemists who are engaged in fertilizer work. Dr. McCandless favors making the solution neutral by analysis, and calculating the exact quantity of ammonia or citric acid to be added. A citrate solution which is neutral b y analysis is distinctly alkaline b y the ordinary indicator, and while i t would be quite a departure from the Official method, i t would a t least insure a greater degree of uniformity than i t is possible to obtain under the present methods. It is fortunate that a slight deviation from strict neutrality has no appreciable effect in the ordinary acidulated goods, b u t in cases of bone, tankage, etc., i t is very important that the solution should be neutral. There is another point that seems to have been overlooked in carrying out this method which causes quite wide variations in results by different analysts; that is, the manner of filtration after digesting with ammonium citrate. I have investigated the question to some extent, and find the following methods of filtration in use in different laboratories. Through asbestos in Hirsch funnel with filter 1 Paper read before the Division of Fertilizer Chemists at Baltimore, December 31, 1908.
pump; through asbestos on carbon filter with filter pump; through filter paper on Hirsch funnel with filter pump; through filter paper in Buchner funnel with filter pump; through filter paper with regular funnel and platinum cone using filter pump ; through folded filters without filter pump. The filter papers used in the above vary from very thin to dense slow filtering papers. Experiments which we have made by these different methods show that the results will vary on some samples of acid phosphate having a high percentage of insoluble from 3 per cent. to I per cent. and on such materials as ground bone, tankage, reduced phosphate, basic slag, etc., it is probable that there would be much larger variations. The exact wording of the “official” method with reference to the filtration is as follows: “ A t the expiration of exactly thirty minutes from the time that the filter and residue are introduced remove the flask from the bath, and immediately filter the contents as rapidly as possible.” Now if this were amended so as to specify the exact method of filtratiun and the kind of paper to be used, much of the confusion in results would be avoided. Taking everything into consideration, this method if properly executed, serves the purpose for which i t was intended in a very satisfactory manner, and these few comments are presented with the hope that this division will take up the question and evolve a method which‘will not only be acceptable to the fertilizer chemists, b u t will be adopted by the Association of Official F. B. CARPENTER. A4griculturalChemists.
COUNCIL ON PHARMACY AND CHEMISTRY, REGULATIONS RELATIVE TO N E W AND NONOFFICIAL REMEDIES. The last meeting of this Council of the American Medical Association was devoted to the discussion of the revision of the rules, and rearrangement of the matter contained in the “New and Non-Official Remedies.” I t was decided that this book shall contain descriptions of the proprietary articles accepted b y the Council and of such simple nonproprietary and unofficial substances as are of sufficient importance. I t was decided that proprietary mixtures unless they show originality and a marked advance over similar products, shall not be included in the main body of the book, but when they conform to the rules, they shall be included in form of an appendix to the book. Rule 5 n a s so amended as to require that the actual identity of the manufacturer of a product be furnished. The Council voted to interpret Rule 8 so that after January first, 1909, pharmaceutical preparations and mixtures will be admitted only under a pharmaceutical title which shall indicate the most potent ingredients. Arbitrary coined titles will not be recognized for Pharmaceutical mixtures. I t was also decided that no pharmaceutical mixture shall be accepted whose name indicates its therapeutic action or is suggestive of the names of diseases or pathologic conditions in which i t is to be used. After January first, 1909, this rulc is to be extended to simple articles. The Council voted to condense Rules 9 and IO to become Rule 9 and adopted a nen Rule, S o . IO, under nhich recognition will be refused to articles which, because of their unscientific composition, are useless or inimical to the best interests of the public or of the medical profession.
